London, Jun 1 (PTI) People who use the internet excessively may experience increased heart rate and blood pressure when they go offline, similar to withdrawal symptoms seen in drug addicts, a new study warns.

“We have known for some time that people who are over- dependent on digital devices report feelings of anxiety when they are stopped from using them, but now we can see that these psychological effects are accompanied by actual physiological changes,” said Phil Reed, professor at Swansea University in the UK.

Researchers, including those from Milan University in Italy, studied about 144 participants, aged between 18 and 33 years.

They measured the heart rate and blood pressure of the participants before and after a brief internet session.

Anxiety and self-reported internet-addiction was also assessed.

The results showed increases in physiological arousal on terminating the internet session for those with problematically high internet usage.

Researchers also found that there was an average three to four per cent increase in heart rate and blood pressure, and in some cases double that figure, immediately on termination of internet use, compared to before using it, for those with digital-behaviour problems.

These increases in heart rate and blood pressure were mirrored by increased feelings of anxiety, researchers said.

However, there were no such changes for participants who reported no internet usage problems.

Although this increase is not enough to be life- threatening, such changes can be associated with feelings of anxiety, and with alterations to the hormonal system that can reduce immune responses, researchers said.

These physiological changes and accompanying increases in anxiety indicate a state like withdrawal seen for many ‘sedative’ drugs, such as alcohol, cannabis, and heroin, and this state may be responsible for some people’s need to re- engage with their digital devices to reduce these unpleasant feelings.